the University of Chicago in 1951, after which he served as chief of the Department of Experimental Psychology at the Walter Reed Institute of Research. From 1963 to 1970 he was the deputy director of the Division of Neuropsychiatry at that institution while also directing the Space Research and Psychopharmacology Laboratories at the University of Maryland. In 1967 he was appointed professor of behavioral biology and director of the Behavioral Biology Research Center at The Johns Hopkins University School of Medicine, a position he holds today. Dr. Brady has extensive experience in many areas of human behavior and has previously served on the National Research Council Committee on Space Biology and Medicine and on the Space and Earth Sciences Advisory Committee of the National Aeronautics and Space Administration.

BRUCE M.COULL, M.D., is professor of neurology and head of the Department of Neurology at the College of Medicine of the Arizona Health Sciences Center. From 1982 to 1995 he served as director of the Comprehensive Stroke Center of Oregon at the Oregon Health Sciences Center, and from 1991 to 1995 he was professor of neurology at the Oregon Health Sciences Center. Dr. Coull is on the editorial boards of four major journals dealing with stroke and related issues. He is a member of the Executive Committee of the American Heart Association’s Stroke Council and has served as the principal investigator or a co-principal investigator on numerous studies of stroke, including the multicenter Stroke Prevention in Atrial Fibrillation (SPAF I, II, and III) study, the National Institute of Neurological Disorders and Stroke-funded Mechanism of Injury and Repair in Ischemic Stroke study, and the North American Symptomatic Carotid Endarterectomy Trial.

N.LYNN GERBER, M.D., graduated from Tufts University Medical School in 1971 and completed a residency in internal medicine at the New England Medical Center, followed by a fellowship in rheumatology at the National Institutes of Health. She then took a residency in physical medicine and rehabilitation at George Washington University, which she completed in 1977. Dr. Gerber is currently chief of the Rehabilitation Department of the Clinical Center of the National Institutes of Health and holds faculty appointments at Georgetown and George Washington Universities. She is board certified in internal medicine, rheumatology, and physical medicine and rehabilitation. She is widely published and has received numerous awards. Much of her work involves the study of mechanics of foot function,